Leadfoot
Jane Goodall of the N&P Forum
The only reason the 340 is the bad *** motor is because they didn't build a 360 during the horsepower era. If they did you wouldn't even be able to give a 340 away.
340 Vs 360
- Thread starter bighammer
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NC Engine Builder
Grumpy Old Man
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technically, your wrong, they built 360s in 71 which was probally the high mark of 340 performance. But they never intended the 360 to be the performance engine, although with compression, cam and headflow, the 360 is every bit as capable.
fishy68
Tyr Fryr's Inc.
Time and time again I run into guys (young and old) that ask what engine is in my Cuda and as soon as I tell them it has a 360 (it's actually a stroked 360 now) they get this look on their face that tells me their not impressed at all (as if I care). Many times they ask "why not a 340" and when I tell them the 360 runs just as good when built equal I can tell their reluctant to believe me. It all comes down to reputation. As mentioned above the 340's were performance engines that womped even a lot of big blocks so they gained a big reputation of being bad to the bone back in the day. The problem is their lack of knowledge in knowing all the same high performance tricks that work on a 340 work on a 360 with very similar results. IMO the 360 will most likely always be doomed to be known as the wimpy little brother to a 340, but we know it's really not.
dbphemi
Well-Known Member
I suggest buying the 360 and putting a 340 air cleaner on it.
DusterKrazy
Well-Known Member
If built similar, the 360 will flat out kick the 340 in the nads. This is assuming similar cam specs, compression..etc. The longer stroke provides more low end torque on the street which is what you want. The 340 has the respect and mojo factor but who cares about that bs?
The 340 is legendary for sure but they are not worth what people price them for. More power for your money with a 360.
The neighbor beside me says, you'll never get respect with your built 318 and 360 stuff. Told him that I didn't care, because when my car runs the number, it tends to shut people up. 360's are very easy to make power with and I'd only buy a 340 if it was real cheap.
The 340 is legendary for sure but they are not worth what people price them for. More power for your money with a 360.
The neighbor beside me says, you'll never get respect with your built 318 and 360 stuff. Told him that I didn't care, because when my car runs the number, it tends to shut people up. 360's are very easy to make power with and I'd only buy a 340 if it was real cheap.
dbphemi
Well-Known Member
340's cost more because there are fewer of them out there. They only made them for 5 years . They only came in performance cars. 360's although great motors were made for over 30 years and came in grocery getters and trucks.
Not only did I put a 340 pie plate on my Magnum 360, I put a 340 Duster stripe down the side of the car, LOL.
For one longer stroke doesn't make more torque displacement does a 0.40" 400 (408 ) RB and a 408 LA has the same torque producing ability because while the crank will multiply the cylinder pressure the RB has a bigger piston (more cylinder pressure) equaling out the the effect.
Secondly its also wrong that an equally build 340/360 that the 360 will kick the 340 or 318 for that matter in the nads because of torque, maybe cause of bad setup but not because of torque because a 400hp engine no matter if its a 2l 318 340 360 440 540 all can accomplish the same amout of work in the same amount of time thats the definition of horsepower= move 33000lb 1 foot in 1 minute. Or cars weight/quarter mile/E.T.
breakstuff
Well-Known Member
I've built a 340 and a 360 both the pretty much the same giving .2 extra compression to the 360. No, I won't share the results. I will say that 3 of my cars are 340s and I will say I was more impressed the the quality of the castings of the 360's.
Yes I always have a problem explaining my ideas,
What im trying to say is many on here believe thats a smaller displacement engine can't compete with a larger diplacement of the same horsepower. They feel the larger engines torque difference at the crank is the end of the story. But torque to the ground is what matters. When gearing lets say a 400HP 340 and 360 in the same or very similar car for quarter mile the 340 gonna require deeper gear to accomplish the same work as the 360. Because any engine with 400HP can accomplish the same amount of work in the same amount of time (HP) eg... propelling your car down the quarter mile at the same E.T. it just require the right gear to do it.
And with the crank stroke same thing, many believe for the same displacement the longer stroke engine will produce more torque but the longer stroke engine will have a smaller piston making the engine transfer less cylinder pressure for the longer stroke to multiple into torque, there for both engines have the same torque output capabilities.
What im trying to say is many on here believe thats a smaller displacement engine can't compete with a larger diplacement of the same horsepower. They feel the larger engines torque difference at the crank is the end of the story. But torque to the ground is what matters. When gearing lets say a 400HP 340 and 360 in the same or very similar car for quarter mile the 340 gonna require deeper gear to accomplish the same work as the 360. Because any engine with 400HP can accomplish the same amount of work in the same amount of time (HP) eg... propelling your car down the quarter mile at the same E.T. it just require the right gear to do it.
And with the crank stroke same thing, many believe for the same displacement the longer stroke engine will produce more torque but the longer stroke engine will have a smaller piston making the engine transfer less cylinder pressure for the longer stroke to multiple into torque, there for both engines have the same torque output capabilities.
Yup. X2
Given equal linear force from the piston, a longer stroke will produce a greater force when measured in foot pounds. Reason can be found in the simplest machine, the lever. At 3.31", the 340 has a mechanical advantage ratio of about .26 to one where the 360 at 3.58" has a ratio of about .30 to one. 1000 pounds of force at the crankpin of the 340 will yield 260 ft/lb. of torque. The same 1000 pounds will result in 300 ft/lb. of torque with the 360.
The .040 larger bore results in less than a 2% increase in piston head area. Undeniably larger/better, but I would have a hard time believing that would offset the torque gains found in the crank stroke. FWIW, small block ford and chev also have 4" bores. Stroke them to the Mopar specs and there would be no difference in their mathematical ability to generate torque.
Which brings you to the real difference. Horsepower will be found in the heads! That is a whole other discussion and it has been gone over many times.
Enough of my soapbox for today. 340, 360, or even the 318! Performance pieces interchange, but there is much more to building an engine. Build for your needs and budget.
carls72dart
Well-Known Member
I'm sure glad I have a Free 70 340 block & crank in my basement and a 360 on an engine stand!! I've been fortunate enough to run both and I've enjoyed them both
MoparDaddy
Damn Right I Carry!
Lol just bore the 360 and tell him it's a stroked 340 and save lots of money at the same time
My friend, you are all over the place here!
A 400 B engine has a 4.34 bore and a 3.375 stroke. Mechanical advantage with this stroke would be .265. Given the same linear force of 1000 pounds this would produce 265 ft/lb. torque. This is bested by the 360 LA!
Boring/stroking and gearing were not in the OP's question, although they are an interesting topic. We would best get back on topic.
LOL.... All the physics... and when the 340 guy and 360 guy have it all figured out, the dude with the 318 beats them both... and Mr. 340 and Mr. 360 are left starring at each other.... HUH?????????.... but the law of physics....!!!! Here, let me help. Science, and the law of physics determined the bumble bee cannot fly because its wings are too small for its body. Oops, somebody forgot to tell the bumble bee he can't fly.... LOL
I am on topic because half the people say 340 will lose to an equally prepared 360 cause of the torque advantage, my point thats wrong both would be equal if both are geared right.
And the notion that the torque advantage comes from the crank is wrong also, you keep on saying a linear force 1000 pounds, there is no linear force in the combustion stroke. Pressure drops rapidly as the piston moves down the stroke. Plus the longer stroke has more piston travel to power and the pressure is being applied at ever changing angles cause of the rod ratio.
DusterKrazy
Well-Known Member
The 318 is a very capable engine. You gotta gear it lower and twist it higher to get her there though...
Well, see here, this speaks volumes.... and I appreciate your respect for 318's. But, in every thread I've ever read, there is a subject that I've never seen mention... and that is.... the consumption in the cylinder! Let me give a small tip: only about 85 % (on average) of what is brought into the cylinder is ACTUALLY burned. The 340 does about 15-20 % more cfm's at 5000 rpm's. Hmmmmmmmmmmm.?????......... So if a 340 is actually only consuming 84%, and a person can get the 318 to burn 98 %, given the fact that heads, cam, intake/carb and exhaust are equal, then the 318 does NOT need to "twist higher". You see, on the dyno, cfm's are measured, efficiency is NOT!!!!!! That's why gross horsepower went away and net came into play. Never mind, I should start a thread called "new light"..... and maybe I will..... hmmmm
DJC
Well-Known Member
Once we get this topic decided we should move on to Republican vs Democrat, or Jesus vs Bhudda...
DusterKrazy
Well-Known Member
1971 340 (underrated) at 275hp and 340 foot pounds or torque. 10:1 compression and yes a larger cylinder bore at 4.04 vs. the 360 at 4.00.
1971 360 made 255hp and 360 foot pounds of torque at a mere 2400 rpm. This is with less than 9:1 compression (like 8.7) and using a 2bbl. carb.
What happens when you add compression (say equal to the 340) to the 360?
I still say that if you take the same car down to similar specs including engine combination, rear gear and trans, my money would be on the 360. We aren't talking a smaller engine with forced induction here of any kind. Then any comparison becomes apples to oranges. An engine isn't a thing but a glorified air pump. The more air you can send through it, the more efficient it becomes.
A smaller engine with the right parts is more capable than a larger with mismatched parts of course but my scenario involves a similar build.
Torque is still king on the street and I can't be convinced that the stroke doesn't make a difference. Cubic inches or cubic dollars. There would be no market for stroker kits if it didn't make a difference.
1971 360 made 255hp and 360 foot pounds of torque at a mere 2400 rpm. This is with less than 9:1 compression (like 8.7) and using a 2bbl. carb.
What happens when you add compression (say equal to the 340) to the 360?
I still say that if you take the same car down to similar specs including engine combination, rear gear and trans, my money would be on the 360. We aren't talking a smaller engine with forced induction here of any kind. Then any comparison becomes apples to oranges. An engine isn't a thing but a glorified air pump. The more air you can send through it, the more efficient it becomes.
A smaller engine with the right parts is more capable than a larger with mismatched parts of course but my scenario involves a similar build.
Torque is still king on the street and I can't be convinced that the stroke doesn't make a difference. Cubic inches or cubic dollars. There would be no market for stroker kits if it didn't make a difference.
Dartnut
Don't hate me because i'm beautiful
Build a 360, the cores are cheaper and more plentiful.
273, I've read your posts and I just wanna soft say you are mistaken.
I'm not going to go into a long winded explaintion.
Spend some time in dyno rooms and read up.
Longer stroke engine deliver more torque down low even if the displacement is the same.
I'm out of this thread. Have fun beating this dead horse yet again, one more time!
I'm not going to go into a long winded explaintion.
Spend some time in dyno rooms and read up.
Longer stroke engine deliver more torque down low even if the displacement is the same.
I'm out of this thread. Have fun beating this dead horse yet again, one more time!
rbdart
Well-Known Member
True story..and torque is what moves things
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